International Chemical Safety Cards TRIMETHYL BORATE ICSC: 0593 Methyl borate Trimethoxyborine C3H9BO3 / B(OCH3)3 Molecular mass: 103.9 ICSC #    0593 CAS #     121-43-7 RTECS # ED5600000 UN #        2416 EC #         005-005-00-1 March 28, 1996 Peer reviewed TYPES OF HAZARD/ EXPOSURE ACUTE HAZARDS/ SYMPTOMS PREVENTION FIRST AID/ FIRE FIGHTING FIRE Flammable. Gives off irritating or toxic fumes (or gases) in a fire. NO open flames, NO sparks, and NO smoking. Foam, alcohol-resistant foam, powder, carbon dioxide. EXPLOSION Vapour/air mixtures are explosive. Closed system, ventilation, explosion-proof electrical equipment and lighting. In case of fire: cool drums, etc., by spraying with water but avoid contact of the substance with water. EXPOSURE  •INHALATION Cough. Sore throat. Ventilation. Fresh air, rest.  •SKIN Redness. Burning sensation. Protective gloves. Rinse skin with plenty of water or shower.  •EYES Redness. Pain. Safety spectacles. First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then take to a doctor.  •INGESTION Burning sensation. Abdominal pain. Do not eat, drink, or smoke during work. Rinse mouth. Refer for medical attention. SPILLAGE DISPOSAL STORAGE PACKAGING & LABELLING Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in dry sand or inert absorbent and remove to safe place. Do NOT wash away into sewer (extra personal protection: self-contained breathing apparatus). Fireproof. Separated from strong oxidants, acids. Dry. Airtight. Xn symbol R: 10-21 S: 2-23-25 UN Hazard Class: 3 UN Packing Group: II SEE IMPORTANT INFORMATION ON BACK ICSC: 0593 Prepared in the context of cooperation between the International Programme on Chemical Safety & the Commission of the European Communities (C) IPCS CEC 1994. No modifications to the International version have been made except to add the OSHA PELs, NIOSH RELs and NIOSH IDLH values.

International Chemical Safety Cards TRIMETHYL BORATE ICSC: 0593 I M P O R T A N T D A T A PHYSICAL STATE; APPEARANCE: COLOURLESS LIQUID. PHYSICAL DANGERS: The vapour is heavier than air and may travel along the ground; distant ignition possible. CHEMICAL DANGERS: The substance decomposes on heating or on burning producing toxic fumes including boron oxide. Reacts with oxidants causing fire and explosion hazard. Reacts with water, moist air and acids to form highly flammable methanol and boric acid. OCCUPATIONAL EXPOSURE LIMITS: TLV not established. ROUTES OF EXPOSURE: The substance can be absorbed into the body by inhalation of its vapour and by ingestion. INHALATION RISK: No indication can be given about the rate in which a harmful concentration in the air is reached on evaporation of this substance at 20°C. EFFECTS OF SHORT-TERM EXPOSURE: The substance irritates the eyes, the skin and the respiratory tract. EFFECTS OF LONG-TERM OR REPEATED EXPOSURE: PHYSICAL PROPERTIES Boiling point: 68°C Melting point: -29°C Relative density (water = 1): 0.915 Solubility in water: reaction Relative vapour density (air = 1): 3.6 Flash point: <27°C ENVIRONMENTAL DATA N O T E S Also consult ICSC # 0057 (methanol) and # 0567 (sodium borate). NFPA Code: H2; F3; R1 ADDITIONAL INFORMATION ICSC: 0593 TRIMETHYL BORATE (C) IPCS, CEC, 1994

IMPORTANT LEGAL NOTICE: Neither NIOSH, the CEC or the IPCS nor any person acting on behalf of NIOSH, the CEC or the IPCS is responsible for the use which might be made of this information. This card contains the collective views of the IPCS Peer Review Committee and may not reflect in all cases all the detailed requirements included in national legislation on the subject. The user should verify compliance of the cards with the relevant legislation in the country of use. The only modifications made to produce the U.S. version is inclusion of the OSHA PELs, NIOSH RELs and NIOSH IDLH values.